William IV of Britain

William IV of the United Kingdom (21 August 1765-20 June 1837) was King of the United Kingdom from 26 June 1830 to 20 June 1837, succeeding George IV and preceding Queen Victoria; he also served as King of Hanover from 26 June 1830 to 20 June 1837, succeeding George IV and preceding Ernest Augustus of Hanover.

Biography
William was born in Buckingham House, London, England on 21 August 1765, the third son of King George III and Charlotte of Mecklenburg-Strelitz. William served in the Royal Navy in North America and the Caribbean in his youth, leading to people nicknaming him "the Sailor King". In 1789, he was created Duke of Clarence and St. Andrews, and he inherited the throne when he was 64 years old, as neither of his brothers had children. William's reign saw the updating of the poor law, the restriction of child labor, the abolition of slavery, and the reform of the electoral system in 1832. He was the last King to appoint a Prime Minister contrary to the will of the Parliament, and, through his brother Prince Adolphus, Duke of Cambridge, he gave Hanover a short-lived liberal constitution. He died in 1837 without legitimate issue, and his niece Victoria became Queen of the United Kingdom.